Document uploading issues

I'm learning as I go and I have a client that I've built a modest CMS for. We're having intermittent problems with the CMS not wanting to upload PDF files. Is there a kind soul on here that's willing to look over my code and give me some feedback? There's a couple pages that you'd need to look over. The basic problem is that the move_uploaded_file() function isn't completing the task. I've gone so far as to chmod the destination directory to 777 and it's still not working...my client is feeling a lot of pressure to get this done so I'm in a pinch. I'd greatly appreciate anyone that has suggestions!!

Please do NOT add a sense of urgency to your posts, it is against forum guidelines, you can however do this in our freelancing forum, which is probably the better method to get your issue fixed a little quicker.

It also might be a good idea to post up the code that you are having issues with - Please don't post up pages and pages of code, atleast try to narrow it down to a problematic chunk of code.